1. Field of the Invention
The present invention relates to a remote control system for remotely controlling a legged moving robot.
2. Description of the Prior Art
There has generally been known a remote control system for remotely controlling legged moving robots such as biped (two-legged) walking robots or the like. The known remote control system includes a robot manipulator having a joystick that is operated by the operator sitting on a seat to give a desired operation command for walking, stopping, bending, or holding an article to the robot for thereby remotely controlling the robot. Based on the supplied operation command, the robot establishes its own target orientation and controls its actual orientation until the target orientation is achieved. Furthermore, the robot has a fail-safe function to automatically stabilize its orientation in order to prevent itself from being excessively tilted and turning over due to a control error made by the operator.
The fail-safe function basically allows the robot to maintain its own orientation stably regardless of control errors made by the operator. However, there are still situations where the robot tends to become unstable in orientation and is inclined to turn over under unexpected external forces applied to the robot as when the robot is controlled trolled to carry a heavy object or the robot accidentally hits some object.
It has been desirable for the conventional remote control system to cause the operator to recognize appropriately a situation w here the robot is unstable under unexpected external forces and also to allow the operator to take some action quickly to correct the orientation of the robot.
There has also been known a remote control system which includes a master unit as a robot manipulator that is worn by the operator and operated to transmit an operator's action to the robot, serving as a slave unit, which also transmits its own action back to the master unit, so that the operator's action and the robot's action will be equalized on the basis of so-called bilateral master-slave principles. Since the bilateral master-slave remote control system basically equalizes the operator's action and the robot's action to each other, the robot itself does not have a function to automatically stabilize its own orientation. While the bilateral master-slave remote control system allows the operator to recognize a change in the orientation of the robot, and even if the orientation change will make the robot unstable, the operator may fail to recognize such robot orientation instability if the operator finds himself stable regardless of the orientation change.